I have done some measurements and the mic was placed in a equilateral triangle from the speaker.
Here is first the EDT
Hz; 8000 4000 2000 1000 500 250 125 62,5
Sec; 0,36 0,36 0,34 0,36 0.3 0.28 0.3 0,28
Here is the energy decay sliced in different frequency from the LEFT speaker and it is exactly the same for the right speaker.
Here is a Impulse response between left and right, overlayed.
Thanks, let me know if I have missed something.